Bupa has chosen Age UK as its partner charity for the next two years, with the aim of raising £1m for the charity.
In addition to fundraising, Bupa's staff will volunteer for Age UK's Call in Time telephone friendship service, as well as taking part in runs and the "Big knit" and "The Big Chinwag" events.
Bupa's 32,000 employees' fundraising efforts will go towards Age UK's Information and advice services, wellness programmes and befriending schemes as well as the Call in Time service.
Laurie Boult, head of fundraising at Age UK said: "We're delighted to have been chosen by Bupa as their first UK-wide charity partner.
Boult added: "With the number of people over 85 set to double in the next 20 years, the need to address issues affecting people in later life is more important now than ever.
"It's a sad fact for example that one million older people go a month or longer without speaking to anyone they know so together, through the funds that we raise, we'll be transforming the health and wellbeing of thousands of older people and addressing issues like this - we can't wait to get started."
Richard Bowden, managing director at Bupa UK said: "We are very excited to be working with Age UK to help improve the lives of older people.
"The fit between our organisations is perfect and through our partnership we want to engage our people, customers and wider society to feel positive about ageing - because with the right planning and support everyone should be able to age well.
"We're ambitious for our partnership, aiming to raise £1million over the next two years."